Jason’s Random Thoughts

Scientists at Kobe University believe there is another planet lurking in the depths of the solar system, possibly two-thirds the size of Earth. While the idea of another “Planet X” lurking around our solar system is hardly new, I’m surprised that it’s coming from scientists in Japan.

Using computer simulations and wonderfully complex calculations the study, led by Kobe University professor Tadashi Mukai, says that it’s only a matter of time before this elusive planet is found.

What’s interesting, though, is the fact that the scientists made an assumption for a planet to be somewhere at the edge of our solar system and programmed that into their simulations. From there, they examined the effect such a body would have on the millions of objects contained within the Kuiper Belt, a region that’s full of “spare parts” that did not survive the planet building process, as well as Pluto and a few other dwarf-planets. After running the simulations threw a few billion years of orbital patterns, they’ve found that their hypothesis matched what we can see with existing debris movements. They go on to say that this ninth planet would have an elliptical solar orbit and make it’s way around the sun every 1,100 years.

What’s really interesting about this is that it shows how little we know about our own solar system. If an entire planet can be hidden from our most sensitive equipment for so long, and completely escape the notice of our world’s tireless astronomers, just imagine what else we could find in our cosmic backyard.

Not The First Planet X

This is not the first time that people have argued about the existence of a Planet X, either. Some scientists have argued that there is a very large planet somewhere beyond Neptune, and was first postulated to explain some of the discrepancies in the orbits of the gas giants, Uranus and Neptune. That said, most of these discrepancies were resolved in the 1980’s when scientists had better access to more sensitive research equipment and was confirmed when Voyagers 1 and 2 made their fly-by in the 90’s.

Interestingly enough, Pluto was initially discovered during the hunt for Planet X, but was not dubbed the missing planet. Eris was also determined not to be this absent world even though it was almost dubbed a planet until the IAU (International Astronomical Union) reclassified the requirements for an object to be considered a planet.

The Planet X debate was thought to have ended in 1991 when researcher Myles Standish used data from Voyager 2 to recalculate Neptune’s effect on Uranus. When Neptune’s proper mass was used, the discrepancies in the outer planets’ orbits vanished. On top of this, there are no discrepancies in the current trajectories of the Pioneer 10 and 11, or Voyager 1 and 2 space probes that can be attributed to the gravitational pull of an, as of yet, unknown object past the Kuiper Belt.

So Where Is It?

The Kuiper Belt seems to end abruptly at about 55 Astronomical Units (1 AU is the distance of the Earth from the Sun). Due to the abrupt termination, there is quite a bit of speculation that this is caused by the presence of an object between the size of Earth and Mars somewhere beyond the edge of the belt. The computer simulation conducted at Kobe University put the planet’s orbit somewhere between 80 and 170 AU, which would make it a solid block of ammonia, ethane and a few other trace elements.

Regardless of whether there is another planet beyond our visibility, I’m glad to see that people are still investing so much time to track all of the objects in our solar system. The most we know about our local corner of the universe, the more we can accomplish in the future.